Why are we here? Evolution’s dirty secrets

The dirty secret of evolution is that it's a lot more like the game of Mousetrap than you might think

Topics: Books, Science, Editor's Picks, Evolution, Carl Sagan, Kurt Vonnegut, ,

Why are we here? Evolution's dirty secrets (Credit: Christian Darkin via Shutterstock/Salon)

Why are we here? Might this all just be a big fluke? Even if evolution is, as Arthur Koestler said, like an “epic recited by a stutterer,” what is the plot? It seemed like God had a good idea, but then he got sidetracked. Where is he going with this thing?

I believe the writer Kurt Vonnegut touched on the heart of this question. Before a full house of mostly women at Smith College, he first drew a chart that graphed stories. On the X axis he drew time, on the Y happiness. By making a line, he showed, he could map any human story. Goldilocks and the Three Bears started off with a jump when she found the house in the woods, it moved higher like a stock as she saw the table place set for her, then higher again as she found her warm bed, before plummeting when the bears came home. The Garden of Eden started off very high, plummeted down, and then flatlined. Vonnegut used a big sheet of paper to mock scientific reductionism and social science in particular. Most stories weren’t so clear-cut or geometric; they were more squiggly.

Then he told about his own days. They often started, he said, despite protests from his wife, who thought he could use his time more wisely, in taking a leisurely walk to the post office to mail a single letter. At the post office he bought a single stamp from the pretty teller. They smiled and he slid her the envelope. Nothing would ever happen, he admitted. But still, that was not his point.

What was it?

“I tell you, we are here on Earth to fart around, and don’t let anybody tell you different.”

* * *

Of course, Vonnegut’s is not the last word on the subject. “We are here,” writes the paleontologist Stephen Jay Gould, “because one odd group of fishes had a peculiar fin anatomy that could transform into legs for terrestrial creatures; because comets struck the earth and wiped out dinosaurs, thereby giving mammals a chance not otherwise available.” Vonnegut’s son, the physician Mark Vonnegut, takes a more ethical slant, emphasizing our emotional and physical interconnectedness. “We are here to help each other get through this thing.” The poet W. H. Auden is only superficially similar: “We were put here on earth to help others. I’m not sure what others were put here for.”



I had a teacher, Don Levine, who taught Avant-Garde Cinema, Madness in Literature, and other fun subjects. One day he informed the class that meaning and moaning share the same root. Although we should be dubious of what Jacques Derrida calls “fabulous etymologies”—words evolve much faster than organisms and are thus even more apt to erase traces of their origins in transit—I would not be surprised. It seems to me that the impulse to do something comes before even the discrete task to be done and is also implicit in the thermodynamic equilibrating of nature, especially the elaborate actions, sometimes including planning, of far-from-equilibrium systems that perish if they lose access to the energy gradients that sustain them. A “forness” or “towardness” blankets life at all levels: physiological, unconscious, and conscious. A couple of days ago, for example, I awoke knowing I had to do something. The unusual part was I did not know which of three things. One, I had jammed my finger in basketball two days before and it was throbbing with pain that could be addressed. Two, my bladder was full. Three, I had a sleep mask on, it was Sunday, I had taken melatonin the night before, the mask had fallen off, and I wanted to get it back on before the morning light stung my eyes. What I noticed was that these three desires—treating the pain in my swollen finger, going to the bathroom, and not having light on my eyes—all vied equally for my attention. None was so strong that it obliterated the others, and I initially was not aware of any of them but only of a general desire that something needed to be done. We might call them “telons,” from the Greek telos, “end” or “goal.”

One way or another some members of life have successfully taken care of their goals for the last 3.8 billion years. In a little-known book that has been considered a Principia for biology, Robert Rosen identifies anticipation as a key property of life. He argues that its ends and means are entailed, that life is noncomputable and naturally purposeful. Rosen points out that when causes and effects are nested together, purposes become real. I too would argue that life’s forwardness and towardness comes before any discrete task—any, that is, except for gradient reduction. As a cyclical system, life’s ends and means must be entailed, but organisms can become their own purposes only within the larger context of gradient destruction in which they are already always engaged.

Try to be completely still. You can’t do it. Your heart beats, you breathe, you continue to metabolize. Even sleeping you produce more entropy than a corpse. This, not reproduction, is the essence of life. It is the essence in that it explains not only what we are, aggregates of cosmically abundant matter like hydrogen and carbon, or how we are, but why we are, to spread energy more rapidly, more long lastingly than would be the case if we were not here. We are manifestations, as my coauthor Eric Schneider says, of the second law.

In one of his early books, “The Cosmic Connection,” my father, Carl Sagan, had written words to the effect that the best evidence extraterrestrials might find that Earth has life would be the spectroscopically measurable excess of atmospheric methane, a product of “bovine flatulence.” Although there are more important biospheric sources of atmospheric methane than the methanogenic archaea in the rumens of cattle, my father’s throwaway phrase is a memorable bit of rhetoric. Whether belching or farting, passing gas produces thermodynamic waste gases. Compared with the oxygen and food we take in, the carbon dioxide and methane and other carbon compounds we put out are in a less energetic state. They are not completely energetically stable, however, as the microbially aided breakdown products of food include tiny amounts of hydrogen, carbon dioxide, and methane that combine in the large intestine with hydrogen sulfide and ammonia to make a redolent, combustible mixture: Relatively stable, if smelly, these compounds can, if provided activation energy, be caused to burn, as the psycho rockabilly crooner Angry Johnny, the lead singer of the Killbillies, demonstrated one night by nonchalantly taking a lighter to his rear end one evening in Hell, his name for his studio in Easthampton. This created an invisible torch at some distance from his pants.

Methane, although a waste produced by cows, termites, swamps, and others, is still highly unstable in the presence of oxygen, which is why intelligent aliens might notice it, this cosmic, spectroscopic equivalent of a fart. Indeed, here is a solution to the Fermi paradox: the aliens have detected us, but don’t want to come close, for fear of Earth’s smell.

The entire genesis of the Gaian idea is that Earth’s atmosphere is out of thermodynamic equilibrium, more complex than it should be, given the rules of chemical mixing. But this persistent admixture is explained by the fact that the living organisms of Earth are open systems. Their complexity bleeds over into the environment, even as they produce more entropy (molecular chaos), mostly as heat, farther out. Life is one of a class of thermodynamic systems that naturally organize themselves as they grow by tapping into, and sometimes depleting, local energy stores.

But excess can be bad. It can be fatal, as in death by drug overdose of a Jimi Hendrix, or worse, it can be speciescidal, as in the overpopulation of a species that uses up all its resources and dies of famine, or becomes prey to an epidemic. Flatulence and laughter represent “human” aspects of any number of processes that naturally arise to perpetuate the universally observed energy-spreading mandate codified by the second law. Moreover, laughter and farting, although they seem to represent more or less random examples of gradient breakdown, are not really. Unlike, say, spontaneous combustion, or world war, or genocide, they represent moderate gradient breakdown; they are examples of stable processes, processes in beings letting out steam, as it were, gradually, and thus not, in all likelihood, endangering themselves or the external gradients that sustain them and around which, quite necessarily, their activities are organized.

It is indeed an amusing astrobiological irony that through a smorgasbord of sphincters comes in the aggregate such gas that it provides, within our atmosphere one-fifth oxygen, with which such gases should react, a kind of chemical signature indicating the presence of intelligent life on Earth. Compounds such as the butyl mercaptan released by skunks, methane released by archaea and belching cows and wetlands, and butyric acid released from mammal skin all react strongly with oxygen but linger in our atmosphere—because life keeps farting them forth into the shared ether of its collective home.

* * *

In 1948 the Dutch artist M. C. Escher made a famous lithograph. Two hands emerge out of sleeves on a piece of paper to draw each other. Ends and means become intricately intercalated in complex cyclical complex systems, tending to obscure the basic operations of those systems, especially when they themselves possess semiotic and interpretive abilities. In the 1790s Immanuel Kant said that the difference between an organism and a watch was that an organism creates all its own parts. An organism, unlike a watch, is “both cause and effect of itself.” Kant, who meditated on the difference between a watch, a mechanism that is made, and an organism, a being that grows, was one of the first to think about self-organization. But he was, I think, a little off, as are those who follow on that train, because the organism is connected to an environment and, indeed, dependent on it and the continuous telic reduction of its energy gradient for its own continued sustenance. The internal nesting of causes and effects obscures a function, or purpose, which becomes far more clear when one takes into account the environment. Kant also described an organism as its own purpose. But there is no self disconnected from the material substrate and energetic flows on which it depends. It only ever cycles in order to reduce ambient gradients.

Kant, aware that religious humanity tended to think of itself as made, like a machine, for a higher being, also focused our attention on the difficulty we have determining purpose. The nestedness of cause and effect in cyclical systems disturbs linear logic in interesting ways. For example, as a cyclical system I may be hungry. Therefore I eat a cupcake. Therefore I am not hungry. If we remove the intermediary behavior, we end up with the logical contradiction, “I am hungry . . . therefore I am not hungry.” Still, it makes perfect sense within the cyclical system of which it is a part.

The cells responsible for clotting blood near a paper cut on your finger, if they were conscious, would not necessarily have a clue what they were up to participating in a cascade of enzymes that stops blood flow and heals the damaged tissue, repairing the wound. The purpose becomes evident only as we move outward to see how the organism functions, not only in terms of itself, which it does do, but also in terms of the environment.

Without knowing, or being familiar with, certain details of the cyclical operation of a complex system, we may completely misrecognize or overanalyze its simple natural function. A story by the great French writer Denis Diderot (1713–1784) beautifully illustrates the point. This story is of a wayward horse ridden by the servant Jacques in the novel “Jacques le fataliste et son maître” (Jacques the fatalist and his master). Jacques, who behaves rebelliously, willfully, even though he believes in fate, as if everything were already written above in the stars, takes orders from his nobleman, who, ironically, although he believes in free will, is more happy-go-lucky, rarely taking any initiative. In any case, Jacques one day is on a horse that appears quite willful and takes him, Jacques, off the beaten path and certainly not where Jacques has been telling him to go. And where he ends up is indeed fateful. The horse, moreover, as if making sure Jacques understands, leads him there not once but twice.

And where does he lead him? The gallows.

Naturally, Jacques believes that the horse is sending some kind of message. And the message is clear; it is one of impending doom. For whom, Jacques doesn’t know. But he cannot help but think that the horse’s repeated purposeful behavior is a sign that the grim reaper may be on Jacques’s tail.

The third time the horse goes off course, Jacques arrives at the property of its previous owner, the executioner. There was nothing sinister in the horse’s purposeful movements: it was simply returning to places it knew well, places where it was used to being cared for and fed.

If Diderot is arguing that the horse’s true purpose is not as ornate as Jacques superstitiously imagined, I am arguing that neither may be ours. We have our little purposes and indeed big purposes, such as finding meaning in life, a purpose that gives us the will to live. But there may be bigger purposes. Indeed, if our immediate purpose is to get a bite to eat or a date, to make money or a baby, or even to raise a family or win a war, if we step back we may be able to see that these take place in a larger frame. They take place in the cosmic context of a naturally telic, purposive universe.

* * *

My limited research suggests that Vonnegut’s humorous and partial nonanswer to why we’re here was not just a throwaway line. He gave it some thought. It was the highlight not just of his lecture but, in a more extended way, of the plot of his novel “Galapagos.” Here he tells the story of rich tourists stranded on an island after the rest of humanity has perished from world war and epidemic. The narrator, the ghost of a shipwrecked sailor who drowned but now speaks from the pink tunnel of the afterlife, tells of how the last old man, feeling responsible for humanity’s future, among other things, takes matters into his own hands, literally, introducing semen into the young women in their slumber to preserve the species. The result is healthy young who possess some odd traits. They evolve hairless and develop an extra layer of blubber. After a few generations, their heads are so pointy that they enter the water without a splash. In a few more, none of them remember their mothers after the age of three. Finally, their only trait that ties them to the species from which they came is that whenever they lie about in the sun and one of them farts, the rest laugh.

Combining the ethical precept that we are to be judged by what we do, not what we say, and the materialistic perspective of modern science that brackets intentions, looks for physical causes, and weighs material evidence, I did a Vonnegutian calculation of my own. I figured that the average human being produces roughly thirteen tons of shit over a lifetime. That’s going too far no doubt, but it could be used to argue, since 99.7 percent of “our” total weight is poop, that that is our purpose.

I am aware of the post hoc ergo propter hoc fallacy that just because something happens after something else does not mean that is why it happened. But it is not that simple in a cyclical system, which we are. The odorless methane and smellier hydrocarbons of flatulence are thermodynamic waste gases. They are produced by cyclical thermodynamic systems during their ongoing operations. These operations, as rarefied and complex as they may have become, continue to perform the basic telic task of the second law. What is humorous about farting is not necessarily its inessentiality as is its status as a sign of our essential nature as thermodynamic systems. All of the living ones produce waste gases. Using solar and chemical energy, bacteria cycle these gases globally. We do not. We are a very partial, incomplete part of this system, and farting secretly alerts us to this outside, our insufficiency within the whole. We exclude what we exclude, but it comes back as a wake-up call: We are missing something, the essence of our nature, which is to reduce gradients and preserve ourselves as gradient-reducing beings. Our telonic nature comes before all discrete tasks. So I would say that Vonnegut, though he was joking, was basically right. We are here to fart around. It is funny because it’s true.

* * *

In “The Biologist’s Mistress” the novelist Tori Alexander writes of how, having converted to atheism in college, and having become an avid Darwinist, she would cross out teleological language in her textbooks, for example, she would change “Birds have feathers in order to keep them warm” to “Birds have feathers which happen to keep them warm.” Replacing purpose with chance in this way removed illicit, outmoded connotations of a hands-on deity unscientifically meddling with lawful nature. Since she grew up in the Bible Belt, she considered rooting out purpose, associated with religious superstition, to be part of her education. Later, however, when she became a novelist, she realized that purposefulness is fundamental to living systems, to the structure of art forms as well as organisms. Artists and organisms incorporate random factors, but they do not do so randomly, but purposefully. Such purposefulness, however, is not theological.

As Stanley N. Salthe, a self-described “apostate from Darwinian theory [who has] described it as part of modernism’s origination myth,” points out, thermodynamics provides a level of final causation that is consistent with a natural law-governed cosmos, a source of purpose that is neither theistic nor evolutionary. Fidgeting such as tapping your foot serves no higher purpose but adds to gradient reduction. Lightning reduces an electrical energy gradient, thought the redox gradient of the blood going to your brain. But these are not the higher forms of purpose we usually associate with a thinking God. They are more like necessary activities in a universe with a cosmic energy mandate. Life shares traits with nonliving systems that maintain complexity and grow to accommodate energy’s tendency to spread. It is a natural form of energy transformation in a thermodynamic universe.

Still, however, the fastest ones—and here we may consider ourselves, in our cosmic context as an energy-finding, energy-degrading system— may compromise their own effectiveness. As the energy theorist and ecological founder, the mathematical polymath and insurance adjuster Alfred Lotka suggested, life seems more to optimize than maximize energy use. In a sort of trial run for what Sigmund Freud would later describe as the reality principle, life has learned, no doubt the hard way, to moderate the taste for resource destruction that nonetheless fuels it.

Entropy production is something that happens anyway—it is codified as the second law of thermodynamics—but complex systems are better at it. They do it more efficiently—more quickly, more long lastingly, or both. From a view that the ghost of Vonnegut may share, there is no divine purpose in the sense of consecrating human beings as a “chosen” species. But there is, as his evolutionary thought experiment, Galapagos, shows, a little purpose, one that, at least in Vonnegut’s capable narrative, both we and our imaginary progeny share. From this admittedly evolutionarily reductionistic perspective, the big difference between us and them is that the big-brained species grew too fast and thus blew its chance, whereas the better swimmers kept things within limits, not becoming too big for their ecological britches. Along with Γνῶθι σεαυτόν, (“Know yourself,)” Μηδὲν ἄγαν—(“Nothing in excess”)—was inscribed in gold at the Oracle of Delphi, near the base of Mount Parnassus in the Valley of Phocis, near a rock called Omphalos, regarded as the center of wisdom in the classical world.

* * *

If you’ve ever seen the Milton Bradley game of Mousetrap, you’ve seen how an initial impetus can lead to a cascade: like a line of dominoes, an initial impetus causes a chain reaction, leading to follow-on actions until the energy is dissipated. Each domino’s fall is caused by the previous domino. Life is different in that the dominoes never stop falling. Life’s trick has been to catch energy and not just send it spinning in a captivating series of Mousetrap-like secondary reactions but—beautifully, amazingly, stupendously—to store some of the energy that it takes in and then, later, exploit that stored inner energy to go out and find another finger (energy source) to push the first domino.

The idea of purpose is usually avoided in science. It seems to imply a mystic reverse causation that cannot be scientific. The reticence is that effects in the material world flow from a prior cause to a future event, while effects in the realm of purpose, which seem to belong only to the realm of the mind, explain present activities in terms of goals not yet achieved. We don’t mind attributing such behavior to us, because that’s how it feels, but we are stingy to see its existence in others, even the “higher” animals (e.g., similar to us). But the truth is, purposive behavior is everywhere in nature and doesn’t require brains. An amoeba swims toward nutrients, a bacterium toward sulfur or oxygen. Sunflowers follow the sun.

A cue ball slamming into an eight ball sends it flying, mechanical cause and effect. But your hand reaching for a key is a different story. The key was lifted because it was your purpose to get it to open the door. This is a very different kind of operation, outside the usual scientific realm of immediate cause and effect. Indeed, most people would think that intention, in the form of wanting something for the future, then achieving it through an act of will, is something that happens only to people and some animals, and God.

The truth is, we act as loops in which past and future are intimately conjoined. We know from our experience the familiar feeling of desiring something and doing it, satisfying a drive. There is nothing mystical about such causation in life.

In Mousetrap, a ball bearing, sent rolling, zigzags down a blue ramp into a red slide. There it trips a yellow lever. Which releases another ball bearing that falls through a miniature plastic bathtub onto a toy blue diving board. This seesaws a green plastic diver into a yellow cup. The cup, vibrating, jostles a yellow pole. Which in turn releases a red mesh bell—the final goal of the whimsical contraption—the fall of the mousetrap.

Why do we find this series of connected actions so intriguing— spellbinding in a way similar to a child arranging and then watching a Slinky curl down the stairs? The reason is that it is kinetically familiar. It is a setup in which a series of actions come together surprisingly to give unity to mechanical behaviors. Energy is gathered and transformed, and its release triggers another phase in an unfolding routine.

Life’s animation is similar. It is as serendipitous as the stair-walking Slinky, as intricately connected as the colorful toys of Mousetrap. Like them, life stores and redeploys energy in series of connected actions.

But the “goal” of life appears not to be to catch a plastic mouse or arrive at the foot of the stairs. Life is like a Slinky, but its parts are connected chemically rather than mechanically, and the final result is not a modulated drop down a discrete number of stairs but continuous energy expenditure via structures that release energy to build new, similar structures.

You are one of these structures.

Excerpted from “Cosmic Apprentice: Dispatches From the Edges of Science” by Dorion Sagan. Published by the University of Minnesota Press. Copyright 2013 by Dorion Sagan. Reprinted with permission of the publisher. All rights reserved.

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